Tufted carpets are widely used in home furnishings and automotive interiors. Much of the art in the design and manufacture of tufted carpets relates to making them dimensionally stable. The carpet backing fabric generally plays a major role in providing dimensional stability. The backing fabrics commonly used are woven fabrics. The most common backing fabric in use today is made from woven strips of polypropylene film. While this backing fabric has proven satisfactory for many applications, it does have disadvantages. The woven polypropylene strips sometimes are not completely hidden by the tufts, a situation referred to as "grin through". Adhesive used to augment the attachment of the carpet yarn to the backing fabric has difficulty penetrating the woven backing fabric to adequately bond the base of the tufts.
In order to circumvent these disadvantages, a needlepunched composite of staple fibers and a plastic net was developed and disclosed in U.S. Pat. No. 4,096,302. In this product, the net provides the dimensional stability while the staple fibers visually blend with the tufting fibers to eliminate "grin through". The relative openness of this composite allows backing adhesive to penetrate through to the tufts.
While carpets are most commonly used as floor coverings, they are frequently used in applications which require them to bend and conform to angles. Examples are the carpeting of stair steps and of the interiors of automobiles. The conformance of standard tufted carpets to shapes is frequently imperfect. The techniques used to make carpets dimensionally stable work against their bending and conforming to different shapes. One technique used to make carpets conform to various shapes is to mold them under heat and pressure, as disclosed for example in U.S. Pat. No. 4,169,176. However, there are many situations where this technique would be unsuitable.